Bipolar electrode and method for producing same

Patent metadata

Field	Value
Publication number	US-9972846-B2
Application number	US-201314408583-A
Country	US
Kind code	B2
Filing date	Jun 20, 2013
Priority date	Jun 20, 2012
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

Bipolar electrode ( 100 ) for use in an electrolysis unit, said bipolar electrode ( 100 ) comprising a planar main body having a first side and a second side, each of said first side and said second side being provided with a corresponding pattern of protrusions ( 125 ), wherein each of said protrusions has a geometrical base within the plane of said planar main body and a substantially planar top side ( 129 ), the orthogonal projection of said top side onto said main body being contained in said geometrical base, and wherein the top sides ( 129 ) of the respective protrusions ( 129 ) of said first side and said second side lie in two planes parallel to said planar main body, the electrode being further characterized by specific shape and orientation requirements. Method for producing the bipolar electrode as above described, which includes an embossing step.

First claim

The invention claimed is:

1. A bipolar electrode for use in an electrolysis unit, said bipolar electrode comprising a planar main body having a first side and a second side, each of said first side and said second side being provided with a corresponding pattern of protrusions, wherein each of said protrusions has a geometrical base within the plane of said planar main body and a substantially planar top side, the orthogonal projection of said top side onto said main body being contained in said geometrical base;
wherein the top sides of the respective protrusions of said first side and said second side lie in two planes parallel to said planar main body;
wherein the base of at least 75% of said protrusions has a convex polygonal shape and wherein the corresponding top side has a shape resulting from a homothetic transformation of said polygonal shape;
and wherein said polygonal shape has at least one side that is oriented in a direction substantially normal to the intended direction of flow, and wherein the total length of said at least one side does not exceed 35% of the perimeter of said polygonal shape, and/or said polygonal shape is oriented in such a way that a vector connecting the centroid of said polygonal shape with a corner of the latter having the smallest internal angle, has a direction that is substantially parallel to the direction of flow;
wherein said pattern of protrusions is such that two sets of straight channels are formed, wherein the channels within each respective set have an axis in a common direction, said common direction having its main component in the intended direction of flow; and
wherein said pattern of protrusions is such that average width of the channels within each respective set increases along said common direction.

2. The bipolar electrode according to claim 1 , wherein the ratio of the area of the planar top side of said protrusions to the area of their respective geometric base, exceeds ¼.

3. The bipolar electrode according to claim 1 , wherein the base of each of said protrusions has a convex polygonal shape and wherein the corresponding top side has a shape resulting from a homothetic transformation of said polygonal shape.

4. The bipolar electrode according to claim 1 , wherein the top side is planar and wherein said polygonal shape has at least one side that is oriented in a direction normal to the intended direction of flow, and wherein the total length of said at least one side does not exceed 35% of the perimeter of said polygonal shape, and/or said polygonal shape is oriented in such a way that a vector connecting the centroid of said polygonal shape with a corner of the latter having the smallest internal angle, has a direction that is parallel to the direction of flow.

5. The bipolar electrode according to claim 1 , wherein said pattern of protrusions is repeated on a smaller scale on said top sides of said protrusions.

6. The bipolar electrode according to claim 1 , wherein the base of at least 75% of said protrusions are shaped as diamonds and wherein the corresponding top side has a shape resulting from a homothetic transformation of said diamonds.

7. The bipolar electrode according to claim 1 , wherein the electrode has substantially the shape of a polygon, and contains depressions located at part of its periphery, along one side of the polygon.

8. An electrolysis unit comprising a plurality of bipolar electrodes according to claim 1 and associated ion exchange membrane placed between said bipolar electrodes, said electrodes being electrically connected in series and arranged in a stack.

9. An energy storage and supply unit comprising the electrolysis unit according to claim 8 , a fuel cell, an electrical current interface, and a hydrogen storage tank; said electrolysis unit being coupled to said electrical current interface for receiving current and to said hydrogen storage tank for storing produced hydrogen; and said fuel cell being coupled to said electrical current interface for supplying current thereto and to said hydrogen storage tank for receiving stored hydrogen.

10. A method for the production of hydrogen comprising using the electrolysis unit of claim 8 .

11. A bipolar electrode for use in an electrolysis unit, said bipolar electrode comprising a planar main body having a first side and a second side, each of said first side and said second side being provided with a corresponding pattern of protrusions, wherein each of said protrusions has a geometrical base within the plane of said planar main body and a substantially planar top side, the orthogonal projection of said top side onto said main body being contained in said geometrical base;
wherein the top sides of the respective protrusions of said first side and said second side lie in two planes parallel to said planar main body;
wherein the base of at least 75% of said protrusions has a convex polygonal shape and wherein the corresponding top side has a shape resulting from a homothetic transformation of said polygonal shape;
and wherein said polygonal shape has at least one side that is oriented in a direction substantially normal to the intended direction of flow, and wherein the total length of said at least one side does not exceed 35% of the perimeter of said polygonal shape, and/or said polygonal shape is oriented in such a way that a vector connecting the centroid of said polygonal shape with a corner of the latter having the smallest internal angle, has a direction that is substantially parallel to the direction of flow; and
wherein said pattern of protrusions is repeated on a smaller scale on said top sides of said protrusions.

12. A bipolar electrode for use in an electrolysis unit, said bipolar electrode comprising a planar main body having a first side and a second side, each of said first side and said second side being provided with a corresponding pattern of protrusions, wherein each of said protrusions has a geometrical base within the plane of said planar main body and a substantially planar top side, the orthogonal projection of said top side onto said main body being contained in said geometrical base;
wherein the top sides of the respective protrusions of said first side and said second side lie in two planes parallel to said planar main body;
wherein the base of at least 75% of said protrusions has a convex polygonal shape and wherein the corresponding top side has a shape resulting from a homothetic transformation of said polygonal shape;
and wherein said polygonal shape has at least one side that is oriented in a direction substantially normal to the intended direction of flow, and wherein the total length of said at least one side does not exceed 35% of the perimeter of said polygonal shape, and/or said polygonal shape is oriented in such a way that a vector connecting the centroid of said polygonal shape with a corner of the latter having the smallest internal angle, has a direction that is substantially parallel to the direction of flow; and
wherein the base of at least 75% of said protrusions are shaped as diamonds and wherein the corresponding top side has a shape resulting from a homothetic transformation of said diamonds.

Assignees

• Solvay

Inventors

• Vandenborre Hugo Jan Baptist
• Dubois Eric
• Zandona Nicola

Classifications

• H01M4/8875

  Methods for shaping the electrode into free-standing bodies, like sheets, films or grids, e.g. moulding, hot-pressing, casting without support, extrusion without support · CPC title

• H01M8/026

  characterised by grooves, e.g. their pitch or depth · CPC title

• H01M8/0204

  Non-porous and characterised by the material · CPC title

• C25B11/02 Primary

  characterised by shape or form · CPC title

• C25B1/46

  in diaphragm cells · CPC title